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    <title>Document</title>
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<body>
    <script>
        var intA=true;
        console.log(typeof intA);
        intA=intA.toString();
        console.log(typeof intA,intA);
        console.log("-----------------");
        var strA="123",strB="abc";
        strA=Number(strA);
        strB=Number(strB);
        console.log(strA,strB);
        console.log("-----------------");
        console.log(isNaN(strA),isNaN(strB));
        console.log(isNaN(strA)?"不是数字":"是一个数字");
        console.log(isNaN(strB)?"不是数字":"是一个数字");
        console.log("-----------------");
        var strC=123,strD={};
        console.log(typeof(strC+strD),(strC+strD));
        console.log("-----------------");
        var intB=10,intC=3;
        console.log(intB%intC);
        intB-=10;
        //相等 intB=intB-10;
        console.log(intB);
    </script>
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